A method for manufacturing a three-dimensional memory device is proposed. The method includes replacing a sacrifice layer with a metal layer after forming a columnar section including a charge storage film and a semiconductor body in a stacked body. The stacked body includes an insulating layer and the sacrifice layer alternately stacked. In such a replace process, a method is also proposed, forming a metal layer via a metal nitride film on an inner surface of an air gap between insulating layers formed by removing the sacrifice layer. With increase of the metal nitride film thickness, the metal layer thickness becomes thin relatively. The metal nitride film is provided also between the columnar section and the metal layer, and functions as a barrier metal. The barrier metal is required to have a thickness sufficient for diffusion prevention of elements contained in the metal layer to the columnar section.